An layered earth model

a pile foundation load model

a shallow tunnel excavation model and an associated support model

together with plane strain model test system for measuring pile foundation load

soil pressure

soil settlement

and support strain are set up. Experiments are conducted to study the influences on soil pressure redistributions

soil set

tunnel crown settlements

and internal forces of the tunnel support caused by a nearby shallow tunnel excavation under the condition of various horizontal and vertical existing pile foundation loads. Moreover

the test process and different working conditions are simulated via the FLAC3D software. The results are as follows: (1) Compared to the tunnel excavation without pre-existing pile foundation loads

pre-existing pile foundation loads can significantly alter the soil pressure redistributions

soil settlements and internal forces of the tunnel support; (2) For pile foundation loads of different length

fixed pile diameter and horizontal position

when the ratio of pile length and tunnel depth is equal to 1.0

it causes a largest influence on the effect of tunnel excavation

in the case of the ratio less than 1.0

the influence decreases with the decrease of the ratio; when the ratio is beyond 1.0

the influence of the pile length change on tunnel excavation effect becomes smaller. (3) For file foundation loads of fixed pile diameter and length

the soil pressure

ground settlement and internal force of tunnel support increase with the decrease of the relative horizontal distance between the pile foundation loads and the tunnel. If the ratio of horizontal distance between the pile foundation loads and the tunnel and tunnel diameter is from 0.5 to 4.0

the tunnel will be in the danger. If the ratio of that is from 4.0 to 6.0

the influence on tunnel caused by the pile foundation loads will become lighter. If the ratio of that is beyond 6.0

the influence can be neglected.